The invention relates to a method of and a device for making perforations in the inner gusset portions of a tubular web of plastics foil which is provided with side gussets.
This constitutes a new aim in the treatment of tubular foil, particularly in view of manufacturing bags. Perforations in the inner gusset portions would be able to serve to remove air from such bags, when filled. They may be provided such that nevertheless it is impossible for liquids, such as for example dew water, as is often formed on the bags in storage, to penetrate.